Light-emitting device and electronic apparatus including same

ABSTRACT

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and including a first layer, wherein the first electrode has a work function value of about −5.5 eV to about −6.1 eV, and the interlayer includes a second layer doped with a non-lead-based perovskite compound.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2021-0046096, filed on Apr. 8, 2021, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

Embodiments of the invention relate generally to display devices, andmore particularly, to a light-emitting device and an electronicapparatus including the same.

Discussion of the Background

Light-emitting devices are self-emissive devices that, as compared withdevices of the related art, have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofluminance, driving voltage, and response speed.

In a light-emitting device, a first electrode is located on a substrate,and a hole transport region, an emission layer, an electron transportregion, and a second electrode are sequentially formed on the firstelectrode. Holes provided from the first electrode move toward theemission layer through the hole transport region, and electrons providedfrom the second electrode move toward the emission layer through theelectron transport region. Carriers, such as holes and electrons,recombine in the emission layer to produce light.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

Light-emitting devices and electronic apparatuses constructed accordingto the principles and illustrative implementations of the inventioninclude a layer doped with a non-lead-based perovskite compound, whichprovides for improved efficiency and lifespan.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

According to one aspect of the invention, a light-emitting deviceincludes: a first electrode; a second electrode facing the firstelectrode; and an interlayer between the first electrode and the secondelectrode and including a first layer, wherein the first electrode has awork function value of about −5.5 eV to about −6.1 eV, and theinterlayer includes a second layer doped with a non-lead-basedperovskite compound.

The first electrode may include an anode, the second electrode mayinclude a cathode, and the light-emitting device may further include ahole transport region between the first electrode and the first layermay include an emission layer and may include a hole injection layer, ahole transport layer, an electron blocking layer, or any combinationthereof.

The first electrode may include an anode, the second electrode mayinclude a cathode, and the light-emitting device may further include anelectron transport region between the second electrode and the firstlayer may include an emission layer and may include a hole blockinglayer, an electron transport layer, an electron injection layer, or anycombination thereof.

The energy level of a valence band of the non-lead-based perovskitecompound may be about −5.5 eV to about −6.3 eV.

The permittivity of the non-lead-based perovskite compound may be about30 F/m or more.

The hole transport region may include the second layer doped with thenon-lead-based perovskite compound.

The at least one of the hole injection layer and hole transport layermay include the second layer doped with the non-lead-based perovskitecompound.

The first electrode may include an indium tin oxide, an indium zincoxide, a tin oxide, a zinc oxide, or any combination thereof.

The non-lead-based perovskite compound may of Formula 1: AaZ, wherein inFormula 1, A is a cation of an alkali metal, Z is an anion, and a is aninteger of 1, 2, or 3.

In Formula 1, the variable a may be 3 and Z may be B₂X₅ ⁻³, a may be 2and Z may be BX₃ ⁻², or a may be 1 and Z may be B₂X₃ ⁻¹, wherein A maybe the cation of the alkali metal, B may be Cu, Ag, or any combinationthereof, and X may be F, Cl, Br, I, or any combination thereof.

In Formula 1, the variable a may be 3 and Z may be BX₅ ⁻³, a may be 2and Z may be BX₄ ⁻², or a may be 1 and Z may be B₂X₅ ⁻¹, wherein A maybe the cation of the alkali metal, B may be Mn, Tl, Zn, Ni, Ce, Pr, Nd,Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or any combination thereof,and X may be F, Cl, Br, I, or any combination thereof.

In Formula 1, the a may be 3 and Z may be BX₆ ⁻³, or a may be 2 and Zmay be BX₅ ⁻², wherein A may be the cation of the alkali metal, B may beIn, Sb, Bi, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, orany combination thereof, and X may be F, Cl, Br, I, or any combinationthereof.

The alkali metal may be Li, Na, K, Rb, Cs, Fr, or any combinationthereof.

The first electrode may include an anode, the second electrode mayinclude a cathode, the interlayer may include a hole injection layer anda hole transport layer, the hole injection layer may include the secondlayer doped with the non-lead-based perovskite compound, and the holeinjection layer and the hole transport layer may include a samecompound.

The second layer doped with the non-lead-based perovskite compound mayhave a thickness of about 1 Å to about 10,000 Å.

The second layer doped with the non-lead-based perovskite compound, thenon-lead-based perovskite compound may have a doping concentration ofabout 1 wt % to about 99 wt %.

The electron transport region may include a metal-containing material.

An electronic apparatus may include the light-emitting device, asdescribed above.

The electronic apparatus may further include a thin-film transistor,wherein the thin-film transistor may include a source electrode and adrain electrode, and the first electrode of the light-emitting devicemay be electrically connected to at least one of the source electrodeand the drain electrode of the thin-film transistor.

The electronic apparatus may further include a color filter, a colorconversion layer, a touch screen layer, a polarizing layer, or anycombination thereof.

It is to be understood that both the foregoing general description andthe following detailed description are illustrative and explanatory andare intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate illustrative embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 is a schematic cross-sectional view of an embodiment of alight-emitting device constructed according to the principles of theinvention.

FIG. 2 is a schematic cross-sectional view of an embodiment of alight-emitting apparatus including a light-emitting device constructedaccording to the principles of the invention.

FIG. 3 is a schematic cross-sectional view of another embodiment of alight-emitting apparatus including a light-emitting device constructedaccording to the principles of the invention.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various embodiments may bepracticed without these specific details or with one or more equivalentarrangements. In other instances, well-known structures and devices areshown in block diagram form in order to avoid unnecessarily obscuringvarious embodiments. Further, various embodiments may be different, butdo not have to be exclusive. For example, specific shapes,configurations, and characteristics of an embodiment may be used orimplemented in another embodiment without departing from the inventiveconcepts.

Unless otherwise specified, the illustrated embodiments are to beunderstood as providing illustrative features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anembodiment may be implemented differently, a specific process order maybe performed differently from the described order. For example, twoconsecutively described processes may be performed substantially at thesame time or performed in an order opposite to the described order.Also, like reference numerals denote like elements, and duplicativeexplanations are omitted to avoid redundancy.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z—axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the term“below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various embodiments are described herein with reference to sectionaland/or exploded illustrations that are schematic illustrations ofidealized embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments disclosed herein should not necessarily beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. In this manner, regions illustrated in the drawings maybe schematic in nature and the shapes of these regions may not reflectactual shapes of regions of a device and, as such, are not necessarilyintended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

According to one aspect of the invention, one or more embodiments of alight-emitting device includes: a first electrode; a second electrodefacing the first electrode; and an interlayer located between the firstelectrode and the second electrode and including an emission layer,wherein the first electrode may have a work function value of about −5.5eV to about −6.1 eV, and the interlayer includes a layer doped with anon-lead-based perovskite compound. In an embodiment, the firstelectrode may be an anode, the second electrode may be a cathode, and ahole transport region located between the first electrode and theemission layer and including a hole injection layer, a hole transportlayer, and an electron blocking layer may be further included.

In an embodiment, the first electrode may be an anode, the secondelectrode may be a cathode, and an electron transport region locatedbetween the second electrode and the first layer in the form of anemission layer and include a hole blocking layer, an electron transportlayer, an electron injection layer, or any combination thereof may befurther included. In an embodiment, an energy level of a valence band ofthe non-lead-based perovskite compound may be about −5.5 eV to about−6.3 eV. As the energy level of the valence band of the non-lead-basedperovskite compound is within the above range, charge may be smoothlyintroduced from the first electrode, which has a work function value ofabout −5.5 eV to about −6.1 eV. For example, the first electrode may bean anode. For example, the charge may be a hole.

In an embodiment, the permittivity of the non-lead-based perovskitecompound may be about 30 farad per meter (F/m) or more. For example, thepermittivity of the non-lead-based perovskite compound may be from about30 F/m to about 40 F/m. The non-lead-based perovskite compound havinghigh permittivity may have ferroelectricity. Therefore, band-bending mayoccur in the layer doped with the non-lead-based perovskite compound andthe surrounding layers under an electric field. As a result, asufficiently thin energy barrier may be formed between layers and chargetunneling may be increased, thereby allowing effective charge transfer.This contributes to the improvement in stability and efficiency of adevice. The non-lead-based perovskite compound may be relatively cheaperthan organic materials of the related art.

In an embodiment, the hole transport region may include a layeroptionally in the form of a second layer doped with the non-lead-basedperovskite compound. For example, the hole injection layer and/or holetransport layer may include the layer doped with the non-lead-basedperovskite compound. For example, the layer doped with thenon-lead-based perovskite compound may be a single layer or may bemulti-layered with two or more layers.

For example, the first electrode and the layer doped with thenon-lead-based perovskite compound may physically contact each other.Because the energy level of the valence band of the non-lead-basedperovskite compound is about −5.5 eV to about −6.3 eV, and the workfunction value of the first electrode is about −5.5 eV to about −6.1 eV,a low energy barrier is formed and charge accumulation occurs less, andthus, deterioration in an interface may be minimized. In addition,because the non-lead-based perovskite compound is relatively moreresistant to oxygen and moisture than organic materials of the relatedart, atmospheric storage stability is excellent and heat deposition ispossible.

In an embodiment, the first electrode may include indium tin oxide(ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), orany combination thereof. For example, the first electrode may be indiumtin oxide (ITO), and the non-lead-based perovskite compound may have apermittivity of about 30 F/m to about 40 F/m.

In an embodiment, the non-lead-based perovskite compound may berepresented by Formula 1:

A_(a)Z   Formula 1

wherein, in Formula 1, A may be a cation of an alkali metal, Z may be ananion, and a may be an integer of 1, 2, or 3. Because the non-lead-basedperovskite compound is neutral as a whole, the sum of the charge of thecation and the charge of the anion is 0. In an embodiment, a may be 3and Z may be B₂X₅ ⁻³; a may be 2, and Z may be BX₃ ⁻²; or a may be 1,and Z may be B₂X₃ ⁻¹, and A is as described above.

The group B may be Cu, Ag, or any combination thereof, and X may be F,Cl, Br, I, or any combination thereof. In an embodiment, a may be 3 andZ may be BX₅ ⁻³; a may be 2 and Z may be BX₄ ⁻²; or a may be 1 and Z maybe B₂X₅ ⁻¹. The variable B may be Mn, Tl, Zn, Ni, Ce, Pr, Nd, Pm, Sm,Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or any combination thereof, and Xmay be F, Cl, Br, I, or any combination thereof.

In an embodiment, a may be 3 and Z may be BX₆ ⁻³; or a may be 2 and Zmay be BX₅ ⁻², and A is as described above. The variable B may be In,Sb, Bi, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or anycombination thereof, and X may be F, Cl, Br, I, or any combinationthereof.

In an embodiment, the alkali metal may be Li, Na, K, Rb, Cs, Fr, or anycombination thereof In an embodiment, the first electrode may be ananode, the second electrode may be a cathode, the interlayer may includea hole injection layer and a hole transport layer, the hole injectionlayer may include the layer doped with the non-lead-based perovskitecompound, and the hole injection layer and the hole transport layer mayinclude a same compound.

When the same compound is Y, for example, the light-emitting deviceaccording to an embodiment may include a first electrode/hole injectionlayer (Y+non-lead-based perovskite compound doping)/hole transport layer(Y) structure. In an embodiment, the thickness of the layer doped withthe non-lead-based perovskite compound may be about 1 angstrom (Å) toabout 10,000 Å. For example, the thickness of the layer doped with thenon-lead-based perovskite compound may be about 100 Å to about 700 Å.For example, the thickness of the layer doped with the non-lead-basedperovskite compound may be about 100 Å to about 400 Å. When thethickness of the layer doped with the non-lead-based perovskite compoundis within the above range, the injection performance of the charge maybe optimized.

In an embodiment, in the layer doped with the non-lead-based perovskitecompound, a doping concentration of the non-lead-based perovskitecompound may be about 1 weight percent (wt %) to about 99 wt %. Forexample, the doping concentration may be about 1 wt % to about 40 wt %.For example, the doping concentration may be about 1 wt % to about 10 wt%. When the doping concentration is within the above range, theinjection performance of the charge may be optimized.

The non-lead-based perovskite compound may be manufactured by using LiF,NaF, KF, RbF, CsF, BeF₂, MgF₂, CaF₂, SrF₂, BaF₂, YbF₂, YbF₃, SmF₂, SmF₃,EuF₂, EuF₃, TmF₂, TmF₃, CuF, T1F, AgF, CdF₂, HgF₂, SnF₂, BiF₃, ZnF₂,MnF₂, FeF₂, GeF₂, CoF₂, NiF₂, AlF₃, ThF₄, UF₃, LiCl, NaCl, KCl, RbCl,CsCl, BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂,YbCl₂, YbCl₃, SmCl₂, SmCl₃,EuCl₂, EuCl₃, TmCl₂, TmCl₃, CuCl, TlCl, AgCl, CdCl₂, HgCl₂, SnCl₂,BiCl₃, ZnCl₂, MnCl₂, FeCl₂, GeCl₂, CoCl₂, NiCl₂, AlCl₃, ThCl₄, UCl₃,LiBr, NaBr, KBr, RbBr, CsBr, BeBrz, MgBrz, CaBrz, SrBr₂, BaBr₂, YbBr₂,YbBr₃, SmBr₂, SmBr₃, EuBr₂, EuBr₃, TmBrz, TmBr₃, CuBr, TlBr, AgBr,CdBr₂, HgBr₂, SnBr₂, BiBr₃, ZnBr₂, MnBr₂, FeBr₂, GeBr₂, CoBrz, NiBr₂,AlBr₃, ThBr₄, UBr₃, LiI, NaI, KI, RbI, CsI, BeI₂, MgI₂, CaI₂, SrI₂,BaI₂, YbI₂, YbI₃, SmI₂, SmI₃, EuI₂, EuI₃, TmI₂, TmI₃, CuI, TlI, AgI,CdI₂, HgI₂, SnI₂, BiI₃, ZnI₂, MnI₂, FeI₂, GeI₂, CoI₂, NiI₂, AlI₃, ThI₄,UI₃, or any combination thereof. As methods of manufacturing thenon-lead-based perovskite compound are known in the art, a detailedexplanation thereof will be omitted herein.

According to another aspect of the invention an electronic apparatus mayinclude the light-emitting device. In an embodiment, the electronicapparatus may further include a thin-film transistor, the thin-filmtransistor may include a source electrode and a drain electrode, and thefirst electrode of the light-emitting device may be electricallyconnected to at least one of the source and drain electrodes of thethin-film transistor. In an embodiment, the electronic apparatus mayfurther include a color filter, a color conversion layer, a touch screenlayer, a polarizing layer, or any combination thereof.

Description of FIG. 1

FIG. 1 is a schematic cross-sectional view of an embodiment of alight-emitting device constructed according to the principles of theinvention.

Particularly, FIG. 1 is a schematic cross-sectional view of alight-emitting device 10 according to an embodiment. The light-emittingdevice 10 may include a first electrode 110, an interlayer 130, and asecond electrode 150. Hereinafter, the structure of the light-emittingdevice 10 according to an embodiment and an illustrative method ofmanufacturing the light-emitting device 10 will be described inconnection with FIG. 1.

First Electrode 110

In FIG. 1, a substrate may be additionally located under the firstelectrode 110 or above the second electrode 150. As the substrate, aglass substrate or a plastic substrate may be used. In one or moreembodiments, the substrate may be a flexible substrate, and may includeplastics with excellent heat resistance and durability, such as apolyimide, a polyethylene terephthalate (PET), a polycarbonate, apolyethylene naphthalate, a polyarylate (PAR), a polyetherimide, or anycombination thereof. The first electrode 110 may be formed by, forexample, depositing or sputtering a material for forming the firstelectrode 110 on the substrate. When the first electrode 110 is ananode, the material for forming the first electrode 110 may be a highwork function material that facilitates injection of holes.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, the material for forming thefirst electrode 110 may include an indium tin oxide (ITO), an indiumzinc oxide (IZO), a tin oxide (SnO₂), a zinc oxide (ZnO), or anycombinations thereof. The first electrode 110 may have a single-layeredstructure consisting of a single layer or a multi-layered structureincluding a plurality of layers. For example, the first electrode 110may have a three-layered structure of an ITO/Ag/ITO.

Interlayer 130

The interlayer 130 may be located on the first electrode 110. Theinterlayer 130 may include an emission layer. The interlayer 130 mayfurther include a hole transport region placed between the firstelectrode 110 and the emission layer and an electron transport regionplaced between the emission layer and the second electrode 150. Theinterlayer 130 may further include, in addition to various organicmaterials, metal-containing compounds such as organometallic compounds,inorganic materials such as quantum dots, and the like. In one or moreembodiments, the interlayer 130 may include i) two or more emissionlayers sequentially stacked between the first electrode 110 and thesecond electrode 150 and ii) a charge generation layer located betweenthe two or more emission layers. When the interlayer 130 includes theemission layer and the charge generation layer as described above, thelight-emitting device 10 may be a tandem light-emitting device.

Hole Transport Region in Interlayer 130

The hole transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer consisting of aplurality of different materials, or iii) a multi-layered structureincluding a plurality of layers including different materials.

The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof. For example, the hole transportregion may have a multi-layered structure including a hole injectionlayer/hole transport layer structure, a hole injection layer/holetransport layer/emission auxiliary layer structure, a hole injectionlayer/emission auxiliary layer structure, a hole transportlayer/emission auxiliary layer structure, or a hole injection layer/holetransport layer/electron blocking layer structure, wherein, in eachstructure, layers are stacked sequentially from the first electrode 110.

The hole transport region may include a compound represented by Formula201, a compound represented by Formula 202, or any combination thereof:

wherein, in Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a C₁-C₂₀ alkylene groupunsubstituted or substituted with at least one R_(10a), a C₂-C₂₀alkenylene group unsubstituted or substituted with at least one R_(10a),a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at leastone R_(10a), or a C₁-C60 heterocyclic group unsubstituted or substitutedwith at least one R_(10a),

xa1 to xa4 may each independently be an integer from 0 to 5,

xa5 may be an integer from 1 to 10,

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a C₃-C₆₀ carbocyclicgroup unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one Rioa,

R₂₀₁ and R₂₀₂ may optionally be linked to each other, via a single bond,a C₁-C₅ alkylene group unsubstituted or substituted with at least oneR_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted withat least one R_(10a), to form a C₈-C₆₀ polycyclic group (for example, acarbazole group or the like) unsubstituted or substituted with at leastone R_(10a) (for example, Compound HT16),

R₂₀₃ and R₂₀₄ may optionally be linked to each other, via a single bond,a C₁-C₅ alkylene group unsubstituted or substituted with at least oneR_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted withat least one R_(10a), to form a C₈-C₆₀ polycyclic group unsubstituted orsubstituted with at least one R_(10a), and

na1 may be an integer from 1 to 4.

In one or more embodiments, each of Formulae 201 and 202 may include atleast one of groups represented by Formulae CY201 to CY217.

The variables R_(10b) and R_(10c) in Formulae CY201 to CY217 are thesame as described in connection with R_(10a), ring CY₂₀₁ to ring CY₂₀₄may each independently be a C₃-C₂₀ carbocyclic group or a C₁-C₂₀heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217may be unsubstituted or substituted with R_(10a).

In one or more embodiments, ring CY₂₀₁ to ring CY₂₀₄ in Formulae CY201to CY217 may each independently be a benzene group, a naphthalene group,a phenanthrene group, or an anthracene group. In one or moreembodiments, each of Formulae 201 and 202 may include at least one ofgroups represented by Formulae CY201 to CY203. In one or moreembodiments, Formula 201 may include at least one of groups representedby Formulae CY201 to CY203 and at least one of groups represented byFormulae CY204 to CY217.

In one or more embodiments, xa1 in Formula 201 may be 1, R₂₀₁ may be agroup represented by one of Formulae CY201 to CY203, xa2 may be 0, andR₂₀₂ may be a group represented by one of Formulae CY204 to CY207. Inone or more embodiments, each of Formulae 201 and 202 may not include agroup represented by one of Formulae CY201 to CY203. In one or moreembodiments, each of Formulae 201 and 202 may not include a grouprepresented by one of Formulae CY201 to CY203, and may include at leastone of groups represented by Formulae CY204 to CY217. In one or moreembodiments, each of Formulae 201 and 202 may not include a grouprepresented by one of Formulae CY201 to CY217.

In an embodiment, the hole transport region may include one of CompoundsHT1 to HT46, 4,4′,4″-tris[phenyl(m-tolyl)amino]triphenylamine(m-MTDATA),1-N,1-N-bis[4-(diphenylamino)phenyl]-4-N,4-N-diphenylbenzene-1,4-diamine(TDATA), 4,4′,4″-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA),bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine (NPB or NPD),N4,N4′-di(naphthalen-2-yl)-N4,N4′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(β-NPB), N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-9,9-spirobifluorene-2,7-diamine(spiro-TPD),N2,N7-di-1-naphthalenyl-N2,N7-diphenyl-9,9′-spirobi[9H-fluorene]-2,7-diamine(spiro-NPB),N,N′-di(1-naphthyl)-N,N-diphenyl-2,2′-dimethyl-(1,1′-biphenyl)-4,4′-diamine(methylated NPB),4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC),N,N,N′,N′-tetrakis(3-methylphenyl)-3,3′-dimethylbenzidine (HMTPD),4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANT/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combinationthereof:

The thickness of the hole transport region may be in a range of about 50Å to about 10,000 Å, for example, about 100 Å to about 4,000 Å. When thehole transport region includes the hole injection layer, the holetransport layer, or any combination thereof, the thickness of the holeinjection layer may be in a range of about 100 Å to about 9,000 Å, forexample, about 100 Å to about 1,000 Å, and the thickness of the holetransport layer may be in a range of about 50 Å to about 2,000 Å, forexample, about 100 Å to about 1,500 Å. When the thicknesses of the holetransport region, the hole injection layer, and the hole transport layerare within these ranges, satisfactory hole transporting characteristicsmay be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer, and the electronblocking layer may block the leakage of electrons from an emission layerto a hole transport region. Materials that may be included in the holetransport region may be included in the emission auxiliary layer and theelectron blocking layer. For example, the hole injection layer and/orhole transport layer may include the layer doped with the non-lead-basedperovskite compound. For example, the layer doped with thenon-lead-based perovskite compound may be a hole injection layer.

Emission Layer in Interlayer 130

When the light-emitting device 10 is a full-color light-emitting device,the emission layer may be patterned into a red emission layer, a greenemission layer, and/or a blue emission layer, according to a sub-pixel.In one or more embodiments, the emission layer may have a stackedstructure of two or more layers of a red emission layer, a greenemission layer, and a blue emission layer, in which the two or morelayers contact each other or are separated from each other. In one ormore embodiments, the emission layer may include two or more materialsof a red light-emitting material, a green light-emitting material, and ablue light-emitting material, in which the two or more materials aremixed with each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant mayinclude a phosphorescent dopant, a fluorescent dopant, or anycombination thereof. The amount of the dopant in the emission layer maybe from about 0.01 to about 15 parts by weight based on 100 parts byweight of the host. In one or more embodiments, the emission layer mayinclude a quantum dot. The emission layer may include a delayedfluorescence material. The delayed fluorescence material may act as ahost or a dopant in the emission layer. The thickness of the emissionlayer may be in a range of about 100 Å to about 1,000 Å, for example,about 200 Å to about 600 Å. When the thickness of the emission layer iswithin these ranges, excellent light-emission characteristics may beobtained without a substantial increase in driving voltage.

Host

In one or more embodiments, the host may include a compound representedby Formula 301 below:

[Ar₃₀₁]_(x11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)   Formula 301

wherein, in Formula 301,

Ar₃₀₁ and L₃₀₁ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

xb11 may be 1, 2, or 3,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted orsubstituted with at least one R_(10a), a C₂-C₆₀ alkenyl groupunsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynylgroup unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀alkoxy group unsubstituted or substituted with at least one R_(10a), aC₃-C₆₀ carbocyclic group unsubstituted or substituted with at least oneR_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted withat least one R_(10a), —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), or —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁ to Q₃₀₃ are each the same as described in connection with Q₁₁ asdescribed herein.

For example, when xbll in Formula 301 is 2 or more, two or more ofAr₃₀₁(s) may be linked to each other via a single bond. In one or moreembodiments, the host may include a compound represented by Formula301-1, a compound represented by Formula 301-2, or any combinationthereof:

In Formulae 301-1 and 301-2,

ring A₃₀₁ to ring A₃₀₄ may each independently be a C₃-C₆₀ carbocyclicgroup unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

X₃₀₁ may be O, S, N-[(L₃₀₄)_(xb4)-R₃₀₄], C(R₃₀₄)(R₃₀₅), orSi(R₃₀₄)(R₃₀₅),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xbl, and R301 are the each same as described herein,

L₃₀₂ to L₃₀₄ are each independently the same as described in connectionwith L₃₀₁,

xb2 to xb4 are each independently the same as described in connectionwith xb1, and

R₃₀₂ to R₃₀₅ and R₃₁₁ to R₃₁₄ are each the same as described inconnection with R₃₀₁.

In one or more embodiments, the host may include an alkali earth metalcomplex, a post-transition metal complex, or any combination thereof. Inone or more embodiments, the host may include a Be complex (for example,Compound H55), an Mg complex, a Zn complex, or any combination thereof.

In an embodiment, the host may include one of Compounds H1 to H124,9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP),1,3-di(carbazole-9-yl)benzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene(TCP), or any combination thereof:

Phosphorescent Dopant

In one or more embodiments, the phosphorescent dopant may include atleast one transition metal as a central metal. The phosphorescent dopantmay include a monodentate ligand, a bidentate ligand, a tridentateligand, a tetradentate ligand, a pentadentate ligand, a hexadentateligand, or any combination thereof. The phosphorescent dopant may beelectrically neutral.

For example, the phosphorescent dopant may include an organometalliccompound represented by Formula 401:

wherein, in Formulae 401 and 402,

M may be transition metal (for example, iridium (Ir), platinum (Pt),palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf),europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium(Tm)),

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1, 2, or3, wherein when xc1 is 2 or more, two or more of L₄₀₁(s) may beidentical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, and whenxc2 is 2 or more, two or more of L₄₀₂(s) may be identical to ordifferent from each other,

X₄₀₁ and X₄₀₂ may each independently be nitrogen or carbon,

ring A₄₀₁ and ring A₄₀₂ may each independently be a C₃-C₆₀ carbocyclicgroup or a C₁-C₆₀ heterocyclic group,

T₄₀₁ may be a single bond, —O—, —S—, —C(═O)—, —N(Q₄₁₁)-,—C(Q₄₁₁)(Q₄₁₂)-, —C(Q₄₁₁)=C(Q₄₁₂)-, —C(Q₄₁₁)=, or ═C═,

X₄₀₃ and X₄₀₄ may each independently be a chemical bond (for example, acovalent bond or a coordination bond), O, S, N(Q₄₁₃), B(Q₄₁₃), P(Q₄₁₃),C(Q₄₁₃)(Q₄₁₄), or Si(Q₄₁₃)(Q₄₁₄),

Q₄₁₁ to Q₄₁₄ are the same as described in connection with Q₁,

R₄₀₁ and R₄₀₂ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup unsubstituted or substituted with at least one R_(10a), a C₁-C₂₀alkoxy group unsubstituted or substituted with at least one R_(10a), aC₃-C₆₀ carbocyclic group unsubstituted or substituted with at least oneR_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted withat least one R_(10a), —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂),—B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), or —P(═O)(Q₄₀₁)(Q₄₀₂),

Q₄₀₁ to Q₄₀₃ are each the same as described in connection with Q₁,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to M in Formula401.

For example, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may becarbon, or ii) each of X₄₀₁ and X₄₀₂ may be nitrogen.

In one or more embodiments, when xc1 in Formula 402 is 2 or more, tworing A₄₀₁(s) in two or more of L₄₀₁(s) may be optionally linked to eachother via T₄₀₂, which is a linking group, and two ring A₄₀₂(s) may beoptionally linked to each other via T₄₀₃, which is a linking group (seeCompounds PD1 to PD4 and PD7). The variables T₄₀₂ and T₄₀₃ are the sameas described in connection with T_(401.)

The group L₄₀₂ in Formula 401 may be an organic ligand. For example,L₄₀₂ may include a halogen group, a diketone group (for example, anacetylacetonate group), a carboxylic acid group (for example, apicolinate group), a —C(═O) group, an isonitrile group, a —CN group, aphosphorus group (for example, a phosphine group, a phosphite group,etc.), or any combination thereof

The phosphorescent dopant may include, for example, one of Compounds PD1to PD25, or any combination thereof:

Fluorescent Dopant

The fluorescent dopant may include an amine group-containing compound, astyryl group-containing compound, or any combination thereof. In one ormore embodiments, the fluorescent dopant may include a compoundrepresented by Formula 501:

wherein, in Formula 501,

Ar₅₀₁, L₅₀₁ to L₅₀₃, R₅₀₁, and R₅₀₂ may each independently be a C₃-C₆₀carbocyclic group unsubstituted or substituted with at least one R_(10a)or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with atleast one R_(10a),

xd1 to xd3 may each independently be 0, 1, 2, or 3, and

xd4 may be 1, 2, 3, 4, 5, or 6.

In one or more embodiments, Ar₅₀₁ in Formula 501 may be a condensedcyclic group (for example, an anthracene group, a chrysene group, or apyrene group) in which three or more monocyclic groups are condensedtogether. In one or more embodiments, xd4 in Formula 501 may be 2.

In one or more embodiments, the fluorescent dopant may include: one ofCompounds FD1 to FD36; DPVBi; DPAVBi; or any combination thereof:

Delayed Fluorescence Material

The emission layer may include a delayed fluorescence material. Asdescribed herein, the delayed fluorescence material may be selected fromcompounds capable of emitting delayed fluorescent light based on adelayed fluorescence emission mechanism. The delayed fluorescencematerial included in the emission layer may act as a host or a dopantdepending on the type of other materials included in the emission layer.

In one or more embodiments, the difference between the triplet energylevel in electron volt (eV) of the delayed fluorescence material and thesinglet energy level (eV) of the delayed fluorescence material may begreater than or equal to about 0 eV and less than or equal to about 0.5eV. When the difference between the triplet energy level (eV) of thedelayed fluorescence material and the singlet energy level (eV) of thedelayed fluorescence material satisfies the above-described range,up-conversion from the triplet state to the singlet state of the delayedfluorescence materials may effectively occur, and thus, the emissionefficiency of the light-emitting device 10 may be improved.

In one or more embodiments, the delayed fluorescence material mayinclude i) a material including at least one electron donor (forexample, a π electron-rich C₃-C₆₀ cyclic group, such as a carbazolegroup) and at least one electron acceptor (for example, a sulfoxidegroup, a cyano group, or a π electron-deficient nitrogen-containingC₁-C₆₀ cyclic group), and ii) a material including a C₈-C₆₀ polycyclicgroup in which two or more cyclic groups are condensed while sharingboron (B).

In one or more embodiments, the delayed fluorescence material mayinclude at least one of Compounds DF1 to DF9:

Quantum Dot

The emission layer may include a quantum dot. The diameter of thequantum dot may be, for example, in a range of about 1 nm to about 10nm. The quantum dot may be synthesized by a wet chemical process, ametal organic chemical vapor deposition process, a molecular beamepitaxy process, or any process similar thereto.

According to the wet chemical process, a precursor material is mixedwith an organic solvent to grow a quantum dot particle crystal. When thecrystal grows, the organic solvent naturally acts as a dispersantcoordinated on the surface of the quantum dot crystal and controls thegrowth of the crystal so that the growth of quantum dot particles can becontrolled through a process which is more easily performed than vapordeposition methods, such as metal organic chemical vapor deposition(MOCVD) or molecular beam epitaxy (MBE), and which requires low costs.

The quantum dot may include a semiconductor compound of Groups II-VI, asemiconductor compound of Groups III-V, a semiconductor compound ofGroups a semiconductor compound of Groups I, III, and VI, asemiconductor compound of Groups IV-VI, an element or a compound ofGroup IV; or any combination thereof.

Examples of the semiconductor compound of Groups II-VI are a binarycompound, such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe,MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS,ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS,CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternarycompound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe,CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; or any combination thereof.

Examples of the semiconductor compound of Groups III-V are a binarycompound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP,InAs, InSb, or the like; a ternary compound, such as GaNP, GaNAs, GaNSb,GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP,InNAs, InNSb, InPAs, InPSb, or the like; a quaternary compound, such asGaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb,GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or thelike; or any combination thereof. The semiconductor compound of GroupsIII-V may further include an element of Group II. Examples of thesemiconductor compound of Groups III-V further including the element ofGroup II are InZnP, InGaZnP, InAlZnP, etc.

Examples of the semiconductor compound of Groups III-VI are: a binarycompound, such as GaS, GaSe, Ga₂Se₃, GaTe, InS, InSe, In₂S₃, In₂Se₃, orInTe; a ternary compound, such as InGaS₃, or InGaSe₃; and anycombination thereof. Examples of the semiconductor compound of Groups I,III, and VI are: a ternary compound, such as AgInS, AgInS₂, CuInS,CuInS₂, CuGaO₂, AgGaO₂, or AgAlO₂; or any combination thereof.

Examples of the semiconductor compound of Groups IV-VI are: a binarycompound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternarycompound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS,SnPbSe, or SnPbTe; a quaternary compound, to such as SnPbSSe, SnPbSeTe,or SnPbSTe; or any combination thereof.

The element or compound of Group IV may include: a single elementcompound, such as Si or Ge; a binary compound, such as SiC or SiGe; orany combination thereof. Each element included in a multi-elementcompound such as the binary compound, the ternary compound, and thequaternary compound, may exist at a uniform concentration or non-uniformconcentration in a particle.

The quantum dot may have a single structure or a dual core-shellstructure. In the case of the quantum dot having a single structure, theconcentration of each element included in the corresponding quantum dotmay be uniform. In one or more embodiments, the material contained inthe core and the material contained in the shell may be different fromeach other. The shell of the quantum dot may act as a protective layerto prevent chemical degeneration of the core to maintain semiconductorcharacteristics and/or as a charging layer to impart electrophoreticcharacteristics to the quantum dot. The shell may be single-layered ormulti-layered. The interface between the core and the shell may have aconcentration gradient in which the concentration of an element existingin the shell is decreased as the element is located closer to the centerof the core.

Examples of the shell of the quantum dot may be an oxide of a metal, ametalloid, or a non-metal, a semiconductor compound, and any combinationthereof. Examples of the oxide of a metal, a metalloid, or a non-metalare a binary compound, such as SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃,Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄, CoO, Co₃O₄, or NiO; a ternary compound,such as MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, or CoMn₂O₄; and any combinationthereof. Examples of the semiconductor compound are, as describedherein, the semiconductor compound of Groups II-VI; the semiconductorcompound of Groups III-V; the semiconductor compound of Groups III-VI;the semiconductor compounds of Groups I, III, and VI; the semiconductorcompound of Groups IV-VI; and any combination thereof In addition, thesemiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe,ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb,AlAs, AlP, AlSb, or any combination thereof.

The full width at half maximum (FWHM) of an emission wavelength spectrumof the quantum dot may be about 45 nm or less, for example, about 40 nmor less, for example, about 30 nm or less, and within these ranges,color purity or color gamut may be increased. In addition, since thelight emitted through the quantum dot is emitted in all directions, thewide viewing angle may be improved.

In addition, the quantum dot may be a generally spherical particle, agenerally pyramidal particle, a generally multi-armed particle, agenerally cubic nanoparticle, a generally nanotube-shaped particle, agenerally nanowire-shaped particle, a generally nanofiber-shapedparticle, or a generally nanoplate-shaped particle.

Because the energy band gap may be adjusted by controlling the size ofthe quantum dot, light having various wavelength bands may be obtainedfrom the quantum dot emission layer. Accordingly, by using quantum dotsof different sizes, a light-emitting device that emits light of variouswavelengths may be implemented. In one or more embodiments, the size ofthe quantum dot may be selected to emit red, green and/or blue light. Inaddition, the size of the quantum dot may be configured to emit whitelight by combining light of various colors.

Electron Transport Region in Interlayer 130

The electron transport region may have: i) a single-layered structureconsisting of a single layer consisting of a single material, ii) asingle-layered structure consisting of a single layer consisting of aplurality of different materials, or iii) a multi-layered structureincluding a plurality of layers including different materials. Theelectron transport region may include a hole blocking layer, an electrontransport layer, an electron injection layer, or any combinationthereof.

In an embodiment, the electron transport region may have an electrontransport layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, andthe like, wherein, for each structure, constituting layers aresequentially stacked from an emission layer. The electron transportregion (for example, the hole blocking layer or the electron transportlayer in the electron transport region) may include a metal-freecompound including at least one π electron-deficient nitrogen-containingC₁-C₆₀ cyclic group.

In an embodiment, the electron transport region may include a compoundrepresented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)   Formula 601

wherein, in Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

xe11 may be 1, 2, or 3,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted withat least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted orsubstituted with at least one R_(10a), —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃),—C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ are each the same as described in connection with Q₁,

xe21 may be 1, 2, 3, 4, or 5, and

at least one of Ar₆₀₁, L_(601,) and R₆₀₁ may each independently be a πelectron-deficient nitrogen-containing C₁-C₆₀ cyclic group unsubstitutedor substituted with at least one R_(10a).

For example, when xe11 in Formula 601 is 2 or more, two or more ofAr₆₀₁(s) may be linked to each other via a single bond. In one or moreembodiments, Ar₆₀₁ in Formula 601 may be a substituted or unsubstitutedanthracene group.

In an embodiment, the electron transport region may include a compoundrepresented by Formula 601-1:

wherein, in Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ are each the same as described in connection with L₆₀₁,

xe611 to xe613 are each the same as described in connection with xe1,

R₆₁₁ to R₆₁₃ are each the same as described in connection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstitutedor substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic groupunsubstituted or substituted with at least one R_(10a).

For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may eachindependently be 0, 1, or 2.

The electron transport region may include one of Compounds ET1 to ET45,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-diphenyl-1,10-phenanthroline (Bphen),tris-(8-hydroxyquinoline)aluminum (Alq₃),bis(2-methyl-8-quinolinolato-N1,08)-(1,1′ -biphenyl-4-olato)aluminum(BAlq),3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), or anycombination thereof:

The thickness of the electron transport region may be from about 100 ○to about 5,000 ○, for example, about 160 ○ to about 4,000 ○. When theelectron transport region includes the hole blocking layer, the electrontransport layer, or any combination thereof, the thickness of the holeblocking layer or electron transport layer may each independently befrom about 20 ○ to about 1,000 ○, for example, about 30 ○ to about 300○, and the thickness of the electron transport layer may be from about100 ○ to about 1,000 ○, for example, about 150 ○ to about 500 ○. Whenthe thicknesses of the hole blocking layer and/or the electron transportlayer are within these ranges, satisfactory electron transportingcharacteristics may be obtained without a substantial increase indriving voltage. The electron transport region (for example, theelectron transport layer in the electron transport region) may furtherinclude, in addition to the materials described above, ametal-containing material.

The metal-containing material may include an alkali metal complex, analkaline earth metal complex, or any combination thereof. The metal ionof an alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion,or a Cs ion, and the metal ion of an alkaline earth metal complex may bea Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligandcoordinated with the metal ion of the alkali metal complex or thealkaline earth-metal complex may include a hydroxyquinoline, ahydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, ahydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole,a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, ahydroxyphenylpyridine, a hydroxyphenylbenzimidazole, ahydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, acyclopentadiene, or any combination thereof.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium quinolate,LiQ) or ET-D2:

The electron transport region may include an electron injection layerthat facilitates the injection of electrons from the second electrode150. The electron injection layer may directly contact the secondelectrode 150. The electron injection layer may have: i) asingle-layered structure consisting of a single layer consisting of asingle material, ii) a single-layered structure consisting of a singlelayer consisting of a plurality of different materials, or iii) amulti-layered structure including a plurality of layers includingdifferent materials. The electron injection layer may include an alkalimetal, an alkaline earth metal, a rare earth metal, an alkalimetal-containing compound, an alkaline earth metal-containing compound,a rare earth metal-containing compound, an alkali metal complex, analkaline earth metal complex, a rare earth metal complex, or anycombination thereof.

The alkali metal may include Li, Na, K, Rb, Cs, or any combinationthereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or anycombination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb,Gd, or any combination thereof. The alkali metal-containing compound,the alkaline earth metal-containing compound, and the rare earthmetal-containing compound may be oxides, halides (for example,fluorides, chlorides, bromides, or iodides), or tellurides of the alkalimetal, the alkaline earth metal, and the rare earth metal, or anycombination thereof.

The alkali metal-containing compound may include alkali metal oxidessuch as Li₂O, Cs₂O, or K₂O, and alkali metal halides such as LiF, NaF,CsF, KF, LiI, NaI, CsI, KI, or any combination thereof. The alkalineearth metal-containing compound may include an alkaline earth metalcompound, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (x is a real numbersatisfying the condition of 0<x<1), Ba_(x)Ca_(1-x)O (x is a real numbersatisfying the condition of 0<x<1), and the like. The rare earthmetal-containing compound may include YbF3, ScF3, Sc203, Y203, Ce2O3,GdF₃, TbF₃, YbI₃, ScI₃, TbI₃, or any combination thereof. In one or moreembodiments, the rare earth metal-containing compound may include alanthanide metal telluride. Examples of the lanthanide metal tellurideare LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe,ErTe, TmTe, YbTe, LuTe, La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃, Sm₂Te₃,Eu₂Te₃, Gd₂Te₃, Tb₂Te₃, Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃, andLu₂Te₃.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include i) one of ions of the alkali metal, thealkaline earth metal, and the rare earth metal and ii), as a ligandbonded to the metal ion, for example, a hydroxyquinoline, ahydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, ahydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole,a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, ahydroxyphenylpyridine, a hydroxyphenylbenzimidazole, ahydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, acyclopentadiene, or any combination thereof.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal-containing compound, analkaline earth metal-is containing compound, a rare earthmetal-containing compound, an alkali metal complex, an alkaline earthmetal complex, a rare earth metal complex, or any combination thereof,as described above. In one or more embodiments, the electron injectionlayer may further include an organic material (for example, a compoundrepresented by Formula 601).

In one or more embodiments, the electron injection layer may consist ofi) an alkali metal-containing compound (for example, an alkali metalhalide), ii) a) an alkali metal-containing compound (for example, analkali metal halide); and b) an alkali metal, an alkaline earth metal, arare earth metal, or any combination thereof In one or more embodiments,the electron injection layer may be a KI:Yb co-deposited layer, anRbI:Yb co-deposited layer, and the like.

When the electron injection layer further includes an organic material,an alkali metal, an alkaline earth metal, a rare earth metal, an alkalimetal-containing compound, an alkaline earth metal-containing compound,a rare earth metal-containing compound, an alkali metal complex, analkaline earth-metal complex, a rare earth metal complex, or anycombination thereof may be homogeneously or non-homogeneously dispersedin a matrix including the organic material.

The thickness of the electron injection layer may be in a range of about1 ○ to about 100 ○, and, for example, about 3 ○ to about 90 ○. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

Second Electrode 150

The second electrode 150 may be located on the interlayer 130. In anembodiment, the second electrode 150 may be a cathode that is anelectron injection electrode. In this embodiment, a material for formingthe second electrode 150 may be a material having a low work function,for example, a metal, an alloy, an electrically conductive compound, orany combination thereof.

The second electrode 150 may include lithium (Li), silver (Ag),magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb),silver-ytterbium (Ag—Yb), an ITO, an IZO, or any combination thereof.The second electrode 150 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode. The secondelectrode 150 may have a single-layered structure, or a multi-layeredstructure including two or more layers.

Capping Layer

A first capping layer may be located outside the first electrode 110,and/or a second capping layer may be located outside the secondelectrode 150. In detail, the light-emitting device 10 may have astructure in which the first capping layer, the first electrode 110, theinterlayer 130, and the second electrode 150 are sequentially stacked inthis stated order, a structure in which the first electrode 110, theinterlayer 130, the second electrode 150, and the second capping layerare sequentially stacked in this stated order, or a structure in whichthe first capping layer, the first electrode 110, the interlayer 130,the second electrode 150, and the second capping layer are sequentiallystacked in this stated order.

Light generated in an emission layer of the interlayer 130 of thelight-emitting device 10 may be extracted toward the outside through thefirst electrode 110, which may be a semi-transmissive electrode or atransmissive electrode, and the first capping layer or light generatedin an emission layer of the interlayer 130 of the light-emitting device10 may be extracted toward the outside through the second electrode 150,which is a semi-transmissive electrode or a transmissive electrode, andthe second capping layer.

Although not wanting to be bound by theory, the first capping layer andthe second capping layer may increase external emission efficiencyaccording to the principle of constructive interference. Accordingly,the light extraction efficiency of the light-emitting device 10 isincreased, thus improving the luminescence efficiency of thelight-emitting device 10.

Each of the first capping layer and second capping layer may include amaterial having a refractive index of about 1.6 or higher (at 589 nm).The first capping layer and the second capping layer may eachindependently be an organic capping layer including an organic material,an inorganic capping layer including an inorganic material, or anorganic-inorganic composite capping layer including an organic materialand an inorganic material.

At least one of the first capping layer and the second capping layer mayeach independently include carbocyclic compounds, heterocycliccompounds, amine group-containing compounds, porphyrin derivatives,phthalocyanine derivatives, naphthalocyanine derivatives, alkali metalcomplexes, alkaline earth metal complexes, or any combination thereof.The carbocyclic compound, the heterocyclic compound, and the aminegroup-containing compound may be optionally substituted with asubstituent including O, N, S, Se, Si, F, Cl, Br, I, or any combinationthereof. In one or more embodiments, at least one of the first cappinglayer and the second capping layer may each independently include anamine group-containing compound.

In one or more embodiments, at least one of the first capping layer andthe second capping layer may each independently include the compoundrepresented by Formula 201, the compound represented by Formula 202, orany combination thereof. In one or more embodiments, at least one of thefirst capping layer and the second capping layer may each independentlyinclude one of Compounds HT28 to HT33, one of Compounds CP1 to CP6,β-N4,N4′-di(naphthalen-2-yl)-N4,N4′-diphenyl[1,1′-biphenyl]-4,4′-diamine(NPB), or any combination thereof:

Electronic Apparatus

The light-emitting device 10 may be included in various electronicapparatuses. In one or more embodiments, the electronic apparatusincluding the light-emitting device 10 may be a light-emittingapparatus, an authentication apparatus, or the like.

The electronic apparatus (for example, light-emitting apparatus) mayfurther include, in addition to the light-emitting device 10, i) a colorfilter, ii) a color conversion layer, or iii) a color filter and a colorconversion layer. The color filter and/or the color conversion layer maybe located in at least one traveling direction of light emitted from thelight-emitting device 10. For example, the light emitted from thelight-emitting device 10 may be blue light. The light-emitting device 10may be the same as described above. In one or more embodiments, thecolor conversion layer may include quantum dots. The quantum dot may be,for example, a quantum dot as described herein.

The electronic apparatus may include a first substrate. The firstsubstrate may include a plurality of subpixel areas, the color filtermay include a plurality of color filter areas respectively correspondingto the subpixel areas, and the color conversion layer may include aplurality of color conversion areas respectively corresponding to thesubpixel areas. A pixel-defining film may be located among the subpixelareas to define each of the subpixel areas. The color filter may furtherinclude a plurality of color filter areas and light-shielding patternslocated among the color filter areas, and the color conversion layer mayinclude a plurality of color conversion areas and light-shieldingpatterns located among the color conversion areas.

The color filter areas (or the color conversion areas) may include afirst area emitting first color light, a second area emitting secondcolor light, and/or a third area emitting third color light, and thefirst color light, the second color light, and/or the third color lightmay have different maximum emission wavelengths from one another. In oneor more embodiments, the first color light may be red light, the secondcolor light may be green light, and the third color light may be bluelight. In one or more embodiments, the color filter areas (or the colorconversion areas) may include quantum dots. In detail, the first areamay include a red quantum dot, the second area may include a greenquantum dot, and the third area may not include a quantum dot. Thequantum dot is the same as described herein. The first area, the secondarea, and/or the third area may each include a scatterer.

In one or more embodiments, the light-emitting device 10 may emit firstlight, the first area may absorb the first light to emit firstfirst-color light, the second area may absorb the first light to emitsecond first-color light, and the third area may absorb the first lightto emit third first-color light. In this regard, the first first-colorlight, the second first-color light, and the third first-color light mayhave different maximum emission wavelengths. In detail, the first lightmay be blue light, the first first-color light may be red light, thesecond first-color light may be green light, and the third first-colorlight may be blue light.

The electronic apparatus may further include a thin-film transistor inaddition to the light-emitting device 10 as described above. Thethin-film transistor may include a source electrode, a drain electrode,and an activation layer, wherein any one of the source electrode and thedrain electrode may be electrically connected to any one of the firstelectrode and the second electrode of the light-emitting device 10.

The thin-film transistor may further include a gate electrode, a gateinsulating film, etc. The activation layer may include a crystallinesilicon, an amorphous silicon, an organic semiconductor, an oxidesemiconductor, or the like.

The electronic apparatus may further include a sealing portion forsealing the light-emitting device 10. The sealing portion and/or thecolor conversion layer may be placed between the color filter and thelight-emitting device 10. The sealing portion allows light from thelight-emitting device 10 to be extracted to the outside, whilesimultaneously preventing ambient air and moisture from penetrating intothe light-emitting device 10. The sealing portion may be a sealingsubstrate including a transparent glass substrate or a plasticsubstrate. The sealing portion may be a thin-film encapsulation layerincluding at least one layer of an organic layer and/or an inorganiclayer. When the sealing portion is a thin film encapsulation layer, theelectronic apparatus may be flexible.

Various functional layers may be additionally located on the sealingportion, in addition to the color filter and/or the color conversionlayer, according to the use of the electronic apparatus. The functionallayers may include a touch screen layer, a polarizing layer, and thelike. The touch screen layer may be a pressure-sensitive touch screenlayer, a capacitive touch screen layer, or an infrared touch screenlayer. The authentication apparatus may be, for example, a biometricauthentication apparatus that authenticates an individual by usingbiometric information of a living body (for example, fingertips, pupils,etc.). The authentication apparatus may further include, in addition tothe light-emitting device 10, a biometric information collector.

The electronic apparatus may take the form of or be applied to variousdisplays, light sources, lighting, personal computers (for example, amobile personal computer), mobile phones, digital cameras, electronicorganizers, electronic dictionaries, electronic game machines, medicalinstruments (for example, electronic thermometers, sphygmomanometers,blood glucose meters, pulse measurement devices, pulse wave measurementdevices, electrocardiogram displays, ultrasonic diagnostic devices, orendoscope displays), fish finders, various measuring instruments, meters(for example, meters for a vehicle, an aircraft, and a vessel),projectors, and the like.

Descriptions of FIGS. 2 and 3

FIG. 2 is a cross-sectional view showing a light-emitting apparatusaccording to an embodiment of the present disclosure.

The light-emitting apparatus 180 of FIG. 2 includes a substrate 100, athin-film transistor (TFT) 200, a light-emitting device 10, and anencapsulation portion 300 that seals the light-emitting device 10.

The substrate 100 may be a flexible substrate, a glass substrate, or ametal substrate. A buffer layer 210 may be formed on the substrate 100.The buffer layer 210 may prevent penetration of impurities through thesubstrate 100 and may provide a substantially flat surface on thesubstrate 100.

The TFT 200 may be located on the buffer layer 210. The TFT 200 mayinclude an activation layer 220, a gate electrode 240, a sourceelectrode 260, and a drain electrode 270. The activation layer 220 mayinclude an inorganic semiconductor such as silicon or a polysilicon, anorganic semiconductor, or an oxide semiconductor, and may include asource region, a drain region and a channel region.

A gate insulating film 230 for insulating the activation layer 220 fromthe gate electrode 240 may be located on the activation layer 220, andthe gate electrode 240 may be located on the gate insulating film 230.An interlayer insulating film 250 may be located on the gate electrode240. The interlayer insulating film 250 may be between the gateelectrode 240 and the source electrode 260 and between the gateelectrode 240 and the drain electrode 270 to provide insulationtherebetween.

The source electrode 260 and the drain electrode 270 may be located onthe interlayer insulating film 250. The interlayer insulating film 250and the gate insulating film 230 may be formed to expose the sourceregion and the drain region of the activation layer 220, and the sourceelectrode 260 and the drain electrode 270 may be in contact with theexposed portions of the source region and the drain region of theactivation layer 220.

The TFT 200 is electrically connected to a light-emitting device 10 todrive the light-emitting device 10, and is covered by a passivationlayer 280. The passivation layer 280 may include an inorganic insulatingfilm, an organic insulating film, or any combination thereof. Alight-emitting device 10 is provided on the passivation layer 280. Thelight-emitting device 10 may include a first electrode 110, aninterlayer 130, and a second electrode 150.

The first electrode 110 may be formed on the passivation layer 280. Thepassivation layer 280 may not completely cover the drain electrode 270and expose a portion of the drain electrode 270, and the first electrode110 may be connected to the exposed portion of the drain electrode 270.

A pixel defining layer 290 including an insulating material may belocated on the first electrode 110. The pixel defining layer 290 mayexpose a region of the first electrode 110, and an interlayer 130 may beformed in the exposed region of the first electrode 110. The pixeldefining layer 290 may be a polyimide or a polyacrylic organic film. Atleast some layers of the interlayer 130 may extend beyond the upperportion of the pixel defining layer 290 to be located in the form of acommon layer. The second electrode 150 may be located on the interlayer130, and a capping layer 170 may be additionally formed on the secondelectrode 150. The capping layer 170 may be formed to cover the secondelectrode 150.

The encapsulation portion 300 may be located on the capping layer 170.The encapsulation portion 300 may be located on a light-emitting device10 to protect the light-emitting device 10 from moisture or oxygen. Theencapsulation portion 300 may include: an inorganic film including asilicon nitride (SiN_(x)), a silicon oxide (SiO_(x)), an indium tinoxide, an indium zinc oxide, or any combination thereof; an organic filmincluding a polyethylene terephthalate, a polyethylene naphthalate, apolycarbonate, a polyimide, a polyethylene sulfonate, apolyoxymethylene, a polyarylate, a hexamethyldisiloxane, an acrylicresin (for example, a polymethyl methacrylate, a polyacrylic acid, orthe like), an epoxy-based resin (for example, an aliphatic glycidylether (AGE), or the like), or any combination thereof; or anycombination of the inorganic film and the organic film.

FIG. 3 is a schematic cross-sectional view of another embodiment of alight-emitting apparatus including a light-emitting device constructedaccording to the principles of the invention.

The light-emitting apparatus 190 of FIG. 3 may be substantiallyidentical to the light-emitting apparatus 180 of FIG. 2, except that alight-shielding pattern 500 and a functional region 400 are additionallylocated on the encapsulation portion 300. The functional region 400 maybe a combination of i) a color filter area, ii) a color conversion area,or iii) a combination of the color filter area and the color conversionarea. In one or more embodiments, the light-emitting device 10 includedin the light-emitting apparatus 190 of FIG. 3 may be a tandemlight-emitting device 10.

Manufacturing Method

Respective layers included in the hole transport region, the emissionlayer, and respective layers included in the electron transport regionmay be formed in a certain region by using one or more suitable methodsselected from vacuum deposition, spin coating, casting,Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, andlaser-induced thermal imaging.

When layers constituting the hole transport region, the emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec, depending on a material to be included in a layer tobe formed and the structure of a layer to be formed. When layersconstituting the hole transport region, the emission layer, and layersconstituting the electron transport region are formed by spin coating,the spin coating may be performed at a coating speed of about 2,000 rpmto about 5,000 rpm and at a heat treatment temperature of about 80° C.to 200° C. by taking into account a material to be included in a layerto be formed and the structure of a layer to be formed.

Definition of Terms

As used herein, the term “energy level” may be expressed in “electronvolt” and both energy level and electron volt may be, independently,abbreviated as “eV”.

As used herein, the term “atom” may mean an element or its correspondingradical bonded to one or more other atoms.

The terms “hydrogen” and “deuterium” refer to their respective atoms andcorresponding radicals with the deuterium radical abbreviated “-D”, andthe terms “—F, —Cl, —Br, and —I” are radicals of, respectively,fluorine, chlorine, bromine, and iodine.

As used herein, a substituent for a monovalent group, e.g., alkyl, mayalso be, independently, a substituent for a corresponding divalentgroup, e.g., alkylene.

The term “interlayer” as used herein refers to a single layer and/or allof a plurality of layers located between a first electrode and a secondelectrode of a light-emitting device.

As used herein, a quantum dot refers to a crystal of a semiconductorcompound, and may include any material capable of emitting light ofvarious emission wavelengths according to the size of the crystal.

The term “C₃-C₆₀ carbocyclic group” as used herein refers to a cyclicgroup consisting of carbon only as a ring-forming atom and having threeto sixty carbon atoms, and the term “C₁-C₆₀ heterocyclic group” as usedherein refers to a cyclic group that has one to sixty carbon atoms andfurther has, in addition to carbon, a heteroatom as a ring-forming atom.The C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group may eachbe a monocyclic group consisting of one ring or a polycyclic group inwhich two or more rings are fused with each other. For example, theC₁-C₆₀ heterocyclic group has 3 to 61 ring-forming atoms.

The “cyclic group” as used herein may include the C₃-C₆₀ carbocyclicgroup, and the C₁-C₆₀ heterocyclic group.

The term “π electron-rich C₃-C₆₀ cyclic group” as used herein refers toa cyclic group that has three to sixty carbon atoms and does not include*—N═*′ as a ring-forming moiety, and the term “π electron-deficientnitrogen-containing C₁-C₆₀ cyclic group” as used herein refers to aheterocyclic group that has one to sixty carbon atoms and includes*—N═*′ as a ring-forming moiety.

For example, the C₃-C₆₀ carbocyclic group may be i) a group T1 or ii) afused cyclic group in which at least two groups T1 are fused, forexample, a cyclopentadiene group, an adamantane group, a norbornanegroup, a benzene group, a pentalene group, a naphthalene group, anazulene group, an indacene group, an acenaphthylene group, a phenalenegroup, a phenanthrene group, an anthracene group, a fluoranthene group,a triphenylene group, a pyrene group, a chrysene group, a perylenegroup, a pentaphene group, a heptalene group, a naphthacene group, apicene group, a hexacene group, a pentacene group, a rubicene group, acoronene group, an ovalene group, an indene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, an indenophenanthrenegroup, or an indenoanthracene group.

The C₁-C₆₀ heterocyclic group may be i) a group T2, ii) a fused cyclicgroup in which at least two groups T2 are fused, or iii) a fused cyclicgroup in which at least one group T2 and at least one group T1 arefused, for example, a pyrrole group, a thiophene group, a furan group,an indole group, a benzoindole group, a naphthoindole group, anisoindole group, a benzoisoindole group, a naphthoisoindole group, abenzosilole group, a benzothiophene group, a benzofuran group, acarbazole group, a dibenzosilole group, a dibenzothiophene group, adibenzofuran group, an indenocarbazole group, an indolocarbazole group,a benzofurocarbazole group, a benzothienocarbazole group, abenzosilolocarbazole group, a benzoindolocarbazole group, abenzocarbazole group, a benzonaphthofuran group, a benzonapthothiophenegroup, a benzonaphthosilole group, a benzofurodibenzofuran group, abenzofurodibenzothiophene group, a benzothienodibenzothiophene group, apyrazole group, an imidazole group, a triazole group, an oxazole group,an isoxazole group, an oxadiazole group, a thiazole group, anisothiazole group, a thiadiazole group, a benzopyrazole group, abenzimidazole group, a benzoxazole group, a benzoisoxazole group, abenzothiazole group, a benzoisothiazole group, a pyridine group, apyrimidine group, a pyrazine group, a pyridazine group, a triazinegroup, a quinoline group, an isoquinoline group, a benzoquinoline group,a benzoisoquinoline group, a quinoxaline group, a benzoquinoxalinegroup, a quinazoline group, a benzoquinazoline group, a phenanthrolinegroup, a cinnoline group, a phthalazine group, a naphthyridine group, animidazopyridine group, an imidazopyrimidine group, an imidazotriazinegroup, an imidazopyrazine group, an imidazopyridazine group, anazacarbazole group, an azafluorene group, an azadibenzosilole group, anazadibenzothiophene group, an azadibenzofuran group, and the like.

The π electron-rich C₃-C₆₀ cyclic group may be i) a group T1, ii) afused cyclic group in which at least two groups T1 are fused with eachother, iii) a group T3, iv) a fused cyclic group in which at least twogroups T3 are fused, or v) a fused cyclic group in which at least onegroup T3 and at least one group T1 are fused, for example, the C₃-C₆₀carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group,an indole group, a benzoindole group, a naphthoindole group, anisoindole group, a benzoisoindole group, a naphthoisoindole group, abenzosilole group, a benzothiophene group, a benzofuran group, acarbazole group, a dibenzosilole group, a dibenzothiophene group, adibenzofuran group, an indenocarbazole group, an indolocarbazole group,a benzofurocarbazole group, a benzothienocarbazole group, abenzosilolocarbazole group, a benzoindolocarbazole group, abenzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophenegroup, a benzonaphthosilole group, a benzofurodibenzofuran group, abenzofurodibenzothiophene group, a benzothienodibenzothiophene group,and the like.

The π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group may bei) a group T4, ii) a fused cyclic group in which at least two groups T4are fused with each other, iii) a fused cyclic group in which at leastone group T4 and at least one group T1 are fused with each other, iv) afused cyclic group in which at least one group T4 and at least one groupT3 are fused with each other, or v) a fused cyclic group in which atleast one group T4, at least one group T1, and at least one group T3 arefused with one another, for example, a pyrazole group, an imidazolegroup, a triazole group, an oxazole group, an isoxazole group, anoxadiazole group, a thiazole group, an isothiazole group, a thiadiazolegroup, a benzopyrazole group, a benzimidazole group, a benzoxazolegroup, a benzoisoxazole group, a benzothiazole group, a benzoisothiazolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, a quinoline group, an isoquinolinegroup, a benzoquinoline group, a benzoisoquinoline group, a quinoxalinegroup, a benzoquinoxaline group, a quinazoline group, a benzoquinazolinegroup, a phenanthroline group, a cinnoline group, a phthalazine group, anaphthyridine group, an imidazopyridine group, an imidazopyrimidinegroup, an imidazotriazine group, an imidazopyrazine group, animidazopyridazine group, an azacarbazole group, an azafluorene group, anazadibenzosilole group, an azadibenzothiophene group, an azadibenzofurangroup, etc.

The group T1 may be a cyclopropane group, a cyclobutane group, acyclopentane group, a cyclohexane group, a cycloheptane group, acyclooctane group, a cyclobutene group, a cyclopentene group, acyclopentadiene group, a cyclohexene group, a cyclohexadiene group, acycloheptene group, an adamantane group, a norbornane (or abicyclo[2.2.1]heptane) group, a norbornene group, abicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, abicyclo[2.2.2]octane group, or a benzene group.

The group T2 may be a furan group, a thiophene group, a 1H-pyrrolegroup, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrolegroup, an imidazole group, a pyrazole group, a triazole group, atetrazole group, an oxazole group, an isoxazole group, an oxadiazolegroup, a thiazole group, an isothiazole group, a thiadiazole group, anazasilole group, an azaborole group, a pyridine group, a pyrimidinegroup, a pyrazine group, a pyridazine group, a triazine group, atetrazine group, a pyrrolidine group, an imidazolidine group, adihydropyrrole group, a piperidine group, a tetrahydropyridine group, adihydropyridine group, a hexahydropyrimidine group, atetrahydropyrimidine group, a dihydropyrimidine group, a piperazinegroup, a tetrahydropyrazine group, a dihydropyrazine group, atetrahydropyridazine group, or a dihydropyridazine group.

The group T3 may be a furan group, a thiophene group, a 1H-pyrrolegroup, a silole group, or a borole group.

The group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazolegroup, a pyrazole group, a triazole group, a tetrazole group, an oxazolegroup, an isoxazole group, an oxadiazole group, a thiazole group, anisothiazole group, a thiadiazole group, an azasilole group, an azaborolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, or a tetrazine group.

The terms “the cyclic group, the C₃-C₆₀ carbocyclic group, the C₁-C₆₀heterocyclic group, the π electron-rich C₃-C₆₀ cyclic group, or the πelectron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as usedherein refer to a group fused with any cyclic group, a monovalent group,or a polyvalent group (for example, a divalent group, a trivalent group,a tetravalent group, etc.), depending on the structure of a formula inconnection with which the terms are used. In one or more embodiments, “abenzene group” may be a bengroup, a phenyl group, a phenylene group, orthe like, which may be easily understood by one of ordinary skill in theart according to the structure of a formula including the “benzenegroup.”

Examples of the monovalent C₃-C₆₀ carbocyclic group and the monovalentC₁-C₆₀ heterocyclic group are a C₃-C₁₀ cycloalkyl group, aCi-Cheterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic fused polycyclic group, and amonovalent non-aromatic fused heteropolycyclic group, and examples ofthe divalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀heterocyclic group are a C₃-C₁₀ cycloalkylene group, a C₁-C₁₀heterocycloalkylene group, a C₃-C₁₀ cycloalkenylene group, a C₁-C₁₀heterocycloalkenylene group, a C₆-C₆₀ arylene group, a C₁-C₆₀heteroarylene group, a divalent non-aromatic fused polycyclic group, anda substituted or unsubstituted divalent non-aromatic fusedheteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic hydrocarbon monovalent group that has one to sixtycarbon atoms, and examples thereof are a methyl group, an ethyl group,an n-propyl group, an isopropyl group, an n-butyl group, a sec-butylgroup, an isobutyl group, a tert-butyl group, an n-pentyl group, atert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentylgroup, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, anisohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptylgroup, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, ann-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group,an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonylgroup, an n-decyl group, an isodecyl group, a sec-decyl group, and atert-decyl group. The term “C₁-C₆₀ alkylene group” as used herein refersto a divalent group having a structure corresponding to the C₁-C₆₀ alkylgroup.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon double bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof are an ethenyl group, a propenyl group, and a butenyl group. Theterm “C₂-C₆₀ alkenylene group” as used herein refers to a divalent grouphaving a structure corresponding to the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a monovalenthydrocarbon group having at least one carbon-carbon triple bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having astructure corresponding to the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by -OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C3-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon cyclic group having 3 to 10 carbon atoms, andexamples thereof are a cyclopropyl group, a cyclobutyl group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctylgroup, an adamantanyl group, a norbornanyl group (orbicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, abicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term“C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent grouphaving a structure corresponding to the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent cyclic group that further includes, in addition to a carbonatom, at least one heteroatom as a ring-forming atom and has 1 to 10carbon atoms, and examples thereof are a 1,2,3,4-oxatriazolidinyl group,a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having a structure corresponding to the C₁-C₁₀ heterocycloalkylgroup.

The term C₃-C₁₀ cycloalkenyl group used herein refers to a monovalentcyclic group that has three to ten carbon atoms and at least onecarbon-carbon double bond in the ring thereof and no aromaticity, andexamples thereof are a cyclopentenyl group, a cyclohexenyl group, and acycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as usedherein refers to a divalent group having a structure corresponding tothe C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent cyclic group that has, in addition to a carbon atom, at leastone heteroatom as a ring-forming atom, 1 to 10 carbon atoms, and atleast one carbon-carbon double bond in the cyclic structure thereof.Examples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having a structurecorresponding to the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having six to sixty carbon atoms,and the term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having six to sixty carbonatoms. Examples of the C₆-C₆₀ aryl group are a phenyl group, apentalenyl group, a naphthyl group, an azulenyl group, an indacenylgroup, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a heptalenyl group, a naphthacenyl group, a picenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, and an ovalenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fusedwith each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system that has, in addition to acarbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used hereinrefers to a divalent group having a heterocyclic aromatic system thathas, in addition to a carbon atom, at least one heteroatom as aring-forming atom, and 1 to 60 carbon atoms. Examples of the C₁-C₆₀heteroaryl group are a pyridinyl group, a pyrimidinyl group, a pyrazinylgroup, a pyridazinyl group, a triazinyl group, a quinolinyl group, abenzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinylgroup, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinylgroup, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinylgroup, a phthalazinyl group, and a naphthyridinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀ heteroarylene group each include two ormore rings, the rings may be fused with each other.

The term “monovalent non-aromatic fused polycyclic group” as used hereinrefers to a monovalent group (for example, having 8 to 60 carbon atoms)having two or more rings fused with each other, only carbon atoms asring-forming atoms, and no aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic fused polycyclicgroup are an indenyl group, a fluorenyl group, a spiro-bifluorenylgroup, a benzofluorenyl group, an indenophenanthrenyl group, and anindeno anthracenyl group. The term “divalent non-aromatic fusedpolycyclic group” as used herein refers to a divalent group having astructure corresponding to a monovalent non-aromatic fused polycyclicgroup.

The term “monovalent non-aromatic fused heteropolycyclic group” as usedherein refers to a monovalent group (for example, having 1 to 60 carbonatoms) having two or more rings fused with each other, at least oneheteroatom other than carbon atoms, as a ring-forming atom, and noaromaticity in its entire molecular structure. Examples of themonovalent non-aromatic fused heteropolycyclic group are a pyrrolylgroup, a thiophenyl group, a furanyl group, an indolyl group, abenzoindolyl group, a naphthoindolyl group, an isoindolyl group, abenzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group,a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, adibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group,an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolylgroup, an azadibenzothiophenyl group, an azadibenzofuranyl group, apyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolylgroup, an oxazolyl group, an isoxazolyl group, a thiazolyl group, anisothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, abenzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, abenzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolylgroup, an imidazopyridinyl group, an imidazopyrimidinyl group, animidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinylgroup, an indeno carbazolyl group, an indolocarbazolyl group, abenzofurocarbazolyl group, a benzothienocarbazolyl group, abenzosilolocarbazolyl group, a benzoindolocarbazolyl group, abenzocarbazolyl group, a benzonaphthofuranyl group, abenzonaphthothiophenyl group, a benzonaphthosilolyl group, abenzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and abenzothienodibenzothiophenyl group. The term “divalent non-aromaticfused heteropolycyclic group” as used herein refers to a divalent grouphaving a structure corresponding to a monovalent non-aromatic fusedheteropolycyclic group.

The term “C₆-C₆₀ aryloxy group” as used herein indicates -OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthgroup” asused herein indicates -SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “C₇-C₆₀ aryl alkyl group” used herein refers to -A₁₀₄A₁₀₅(where A₁₀₄ may be a C₁-C₅₄ alkylene group, and A₁₀₅ may be a C₆-C₅₉aryl group), and the term C₂-C₆₀ heteroaryl alkyl group” used hereinrefers to -A₁₀₆A₁₀₇ (where A₁₀₆ may be a C₁-C₅₉ alkylene group, and A₁₀₇may be a C₁-C₅₉ heteroaryl group).

The term “R_(10a)” as used herein refers to:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or anitro group,

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, ora C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthgroup, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂),—C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof,

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthgroup, a C₇-C₆₀ aryl alkyl group, or aC₂-C₆₀ heteroaryl alkyl group, each unsubstituted or substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthgroup, aC₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group,—Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

The variables Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ usedherein may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I;a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; aC₂-C₆₀ alkenyl group; a C₂-C60 alkynyl group; a C₁-C₆₀ alkoxy group; aC₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, eachunsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, orany combination thereof; a C₇-C₆₀ arylalkyl group; or a C₂-C₆₀heteroarylalkyl group.

The term “heteroatom” as used herein refers to any atom other than acarbon atom. Examples of the heteroatom are O, S, N, P, Si, B, Ge, Se,and any combination thereof.

The term “the third-row transition metal” used herein includes hafnium(Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium(Ir), platinum (Pt), gold (Au), and the like.

As used herein, the term “Ph” refers to a phenyl group, the term “Me”refers to a methyl group, the term “Et” refers to an ethyl group, theterm “ter-Bu” or “Bu^(t)” refers to a tert-butyl group, and the term“OMe” refers to a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl groupsubstituted with a phenyl group.” In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group” as used herein refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a substituted phenyl group having, as a substituent, a C₆-C₆₀aryl group substituted with a C₆-C₆₀ aryl group.

The maximum number of carbon atoms in this substituent definitionsection is an example only. In an embodiment, the maximum carbon numberof 60 in the C₁-C₆₀ alkyl group is an example, and the definition of thealkyl group equally applies to a C₁-C₂₀ alkyl group. The same alsoapplies to other cases.

The symbols * and *′ as used herein, unless defined otherwise, eachrefer to a binding site to a neighboring atom in a correspondingformula.

Hereinafter, a compound made according to the principles and embodimentsand a light-emitting device including the compound made according toembodiments will be described in detail with reference to Examples.

Examples Manufacture of Light-Emitting Device Comparative Example 1

As an anode, a glass substrate with 15 Ωcm² (1,200 Å) ITO thereon, whichwas manufactured by Corning Inc., was cut to a size of 50 mm×50 mm×0.7mm, and the glass substrate was sonicated by using isopropyl alcohol andpure water for 5 minutes each, and then ultraviolet (UV) light wasirradiated for 30 minutes thereto and ozone was exposed thereto forcleaning. Then, the resultant glass substrate was loaded onto a vacuumdeposition apparatus.

The compounds HT1 and p-dopant1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) at (5%) weredeposited on the substrate to form a hole injection layer having athickness of 150 Å. Subsequently, the compound HT1 was vacuum-depositedthereon to form a hole transport layer having a thickness of 200 Å.

On the hole transport layer, Compound 100 as a host and fluorescentdopant Compound 200 as a dopant were co-deposited to a weight ratof 97:3to form an emission layer having a thickness of 100 Å.

The compound 2,4,6-tris(3-phenylphenyl)-1,3,5-triazine (T2T) wasvacuum-deposited on the emission layer to form a hole blocking layerhaving a thickness of 100 Å. TPM-TAZ and Liq were deposited on the holeblocking layer to a weight rat io of 5:5 to form an electron transportlayer having a thickness of 300 Å.

Yb was vacuum-deposited on the electron transport layer to form a layerhaving a thickness of 10 Å, AgMg was vacuum-deposited thereon to form acathode having a thickness of 100 Å, and CPL was deposited thereon toform a capping layer having a thickness of 700 Å, thereby manufacturinga light-emitting device.

Comparative Example 2

Light-emitting devices were manufactured in the same manner as inComparative Example 1, except that, as a hole injection layer, onlyCs₃Cu₂I₅ was used instead of the compound HT1 and p-dopant HAT-CN (5%).

Example 1

Light-emitting devices were manufactured in the same manner as inComparative Example 1, except that, as a hole injection layer, HT1 andCs₃Cu₂I₅ (5%) were used.

The work function value of ITO was −5.9 eV, and the valence band energylevel of Cs₃Cu₂I₅ was −6.0 eV.

The permittivity of Cs₃Cu₂I₅ was 32.5 F/m.

To evaluate luminescence characteristics of the light-emitting devicesmanufactured according to Comparative Examples 1 and 2 and Example 1,the voltage at the current density of 10 mA/cm², efficiency, andlifespan thereof were measured.

The efficiency, etc. of the light-emitting devices were measured usingmeasurement device C9920-2-12 of Hamamatsu Photonics Inc.

The results are shown in Table 1 below.

TABLE 1 Driving Color voltage (V) Efficiency coordinates Lifespan@400nit@10 mA (Cd/A) (B y) (~97%) ΔV (@500 hr) Comparative 11.3 22.1 0.125 450hr   1 V Example 1 Comparative 11.0 22.9 0.125 470 hr 0.7 V Example 2Example 1 10.5 24.5 0.125 550 hr 0.2 V (ΔV indicates the change involtage after 500 hours)

Table 1 shows that the light-emitting device according to Example 1 asdescribed herein has better performance than that of the light-emittingdevices of Comparative Examples 1 and 2. Specifically, thelight-emitting device of Example 1, which includes a layer doped with anon-lead-based perovskite compound, shows significantly and unexpectedlyimproved efficiency and lifespan compared to the Comparative Examples 1and 2.

Although certain embodiments and implementations have been describedherein, other embodiments and modifications will be apparent from thisdescription. Accordingly, the inventive concepts are not limited to suchembodiments, but rather to the broader scope of the appended claims andvarious obvious modifications and equivalent arrangements as would beapparent to a person of ordinary skill in the art.

What is claimed is:
 1. A light-emitting device comprising: a firstelectrode; a second electrode facing the first electrode; and aninterlayer located between the first electrode and the second electrodeand including an emission layer, wherein the first electrode has a workfunction value of about −5.5 eV to about −6.1 eV, and the interlayerincludes a layer doped with a non-lead-based perovskite compound.
 2. Thelight-emitting device of claim 1, wherein the first electrode comprisesan anode, the second electrode comprises a cathode, and thelight-emitting device further includes a hole transport region betweenthe first electrode and the emission layer and includes a hole injectionlayer, a hole transport layer, an electron blocking layer, or anycombination thereof.
 3. The light-emitting device of claim 1, whereinthe first electrode comprises an anode, the second electrode comprises acathode, and the light-emitting device further includes an electrontransport region between the second electrode and the emission layer andincludes a hole blocking layer, an electron transport layer, an electroninjection layer, or any combination thereof.
 4. The light-emittingdevice of claim 1, wherein an energy level of a valence band of thenon-lead-based perovskite compound is about −5.5 eV to about −6.3 eV. 5.The light-emitting device of claim 1, wherein a permittivity of thenon-lead-based perovskite compound is about 30 F/m or more.
 6. Thelight-emitting device of claim 2, wherein the hole transport regionincludes the layer doped with the non-lead-based perovskite compound. 7.The light-emitting device of claim 2, wherein at least one of the holeinjection layer and hole transport layer includes the layer doped withthe non-lead-based perovskite compound.
 8. The light-emitting device ofclaim 1, wherein the first electrode comprises an indium tin oxide, anindium zinc oxide, a tin oxide, a zinc oxide, or any combinationthereof.
 9. The light-emitting device of claim 1, wherein thenon-lead-based perovskite compound is of Formula 1:AaZ   Formula 1 wherein in Formula 1, A is a cation of an alkali metal,Z is an anion, and a is an integer of 1, 2, or
 3. 10. The light-emittingdevice of claim 9, wherein a is 3 and Z is B₂X₅ ⁻³, a is 2 and Z is BX₃⁻², or a is 1 and Z is B₂X₃ ⁻¹, wherein A is the cation of the alkalimetal, B is Cu, Ag, or any combination thereof, and X is F, Cl, Br, I,or any combination thereof.
 11. The light-emitting device of claim 9,wherein a is 3 and Z is BX₅ ⁻³, a is 2 and Z is BX₄ ⁻², or a is 1 and Zis B₂X₅ ⁻¹, wherein A is the cation of the alkali metal, B is Mn, Tl,Zn, Ni, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or anycombination thereof, and X is F, Cl, Br, I, or any combination thereof.12. The light-emitting device of claim 9, wherein a is 3 and Z is BX₆⁻³, or a is 2 and Z is BX₅ ⁻², wherein A is the cation of the alkalimetal, B is In, Sb, Bi, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm,Yb, Lu, or any combination thereof, and X is F, Cl, Br, I, or anycombination thereof.
 13. The light-emitting device of claim 9, whereinthe alkali metal is Li, Na, K, Rb, Cs, Fr, or any combination thereof.14. The light-emitting device of claim 1, wherein the first electrodecomprises an anode, the second electrode comprises a cathode, theinterlayer includes a hole injection layer and a hole transport layer,the hole injection layer includes the layer doped with thenon-lead-based perovskite compound, and the hole injection layer and thehole transport layer include a same compound.
 15. The light-emittingdevice of claim 1, wherein the second layer doped with thenon-lead-based perovskite compound has a thickness of about 1 Å to about10,000 Å.
 16. The light-emitting device of claim 1, wherein, in thelayer doped with the non-lead-based perovskite compound, thenon-lead-based perovskite compound has a doping concentration of about 1wt % to about 99 wt %.
 17. The light-emitting device of claim 3, whereinthe electron transport region comprises a metal-containing material. 18.An electronic apparatus comprising the light-emitting device of claim 1.19. The electronic apparatus of claim 18, further comprising a thin-filmtransistor, wherein the thin-film transistor includes a source electrodeand a drain electrode, and the first electrode of the light-emittingdevice is electrically connected to at least one of the source electrodeand the drain electrode of the thin-film transistor.
 20. The electronicapparatus of claim 18, further comprising a color filter, a colorconversion layer, a touch screen layer, a polarizing layer, or anycombination thereof.